Although the safety properties of current lithium-ion batteries have greatly improved, when a battery is improperly overcharged or short circuited, the improper use may still lead to accidents such as smoke, flames, or explosion, etc. Improving the property of the electrolyte is an important method of enhancing the safety properties of batteries. By adding biphenyl and cyclohexylbenzene, overcharge can be effectively curbed, thereby enhancing the safety properties. However, that will affect the cycle and low-temperature properties of batteries.